The submitted invention provides an optical measuring method to measure relative angles between a measuring device and a measuring point by using a band of fanned beams which are emitted from the measuring device and said beams are being thrown back by reflectors installed at the measuring points, whereby the emitting light beam is rotated around the axis of the measuring device, and said light beam passes a predetermined angle range at the beginung in relation to the measuring device, said angle being measured by counting clock pulses until said light beam has reached the end of the angle range, and whereby the determined counter readings are recorded, said counter readings are obtained by a reflected light beam thrown back and the relative angles are calculated by interpretation of the ratio of the counter readings, and furthermore there is included a measuring device to implement said optical measuring method.
A similar method has been noted in patent registration WO 94/00778, U.S. Pat. No. 5,587,787. Said patent relates to a method to measure angles between a measuring platform and a measuring point, whereby a fanned light beam in a level band is rotated around the vertical axis of said measuring platform and where said light beam is thrown back to the measuring platform by reflectors instaled at the measuring points. There is a counter device on the measurig platform which begins to count pulses of the passing fanned light beam at a defined starting position and which registers counter readings when receiving a reflecting light beam. The relative angle between the reflector and the starting position of the measuring platform can be computed by using the ratio of counter readings.
It has been noticed, however, that the accuracy of this method does not meet necessary requirements by using various ratios of the measuring platform especially in relation to the reflectors and moving measuring platform. It is also not possible to calculate the direct distance between measuring platform and reflectors with known methods and devices. This is only possible with separate measuring means.